Roller grinding-mill



'(NoMo de L) v D; CALL-EN. ROLLE NDING MILL.

Patented DemZO, 1892.

Unrrnn STATES Farmer Genres,

DANIEL ALBERT SOALLEN, OF ELLICOTT CITY, MARYLAND.

ROLLER GRINDING-MILL.

SPECIFICATION forming part of Letters Patent No. 488,455, dated December20, 1892.

Application filed December 4, 1886. Serial No. 220,667. (No model.)

To all whom, it may concern.-

Be it known that I, DANIEL ALBERT SCAL- LEN, of Ellicott City, in thecounty of Howard and State of Maryland,have invented certain newImprovements in Roller Grinding-Mills, of which the following is aspecification.

Grinding mills are commonly constructed at the present day with rollshaving smooth surfaces, and with scrapers and brushes to remove theadhering material from the rolls.

In practice it is found that for various reasons, under the dilferentconditions encountered, the scrapers fail to give satisfaction. To avoidthe usual troubles I make use of a scraper of leather sustained byadjusting devices as hereinafter explained; and in order to admit of thescraper being applied conveniently to existing millsI construct thesupport so that it may be lengthened and shortened to suit the width ofdiiferent mills.

In the accompanying drawings,-Figure l is a vertical cross-section of apair of rolls and my scrapers thereunder. Fig. 2 is an elevation of thesame. Figs. 3 and 4 are views showing details of the scraper supports.

A A, represent the grinding rolls which may be constructed, arranged,supported and driven in the ordinary manner; B B, the sides of the mainframe, and O C,the scrapers lying one beneath and lengthwise of eachroll.

The scraper proper consists of a narrow sheet or strip of hard leather,such as common sole leather, presented edgewise against the roll. Thisstrip is seated in a groove in a stationary supporting bar I), and isconfined and sustained therein by a thin and flexible underlying platea, and a side plate (Z, both of which are adjustable by means ofset-screws e and f, seated in bar I) as shown. By properly adjustingthese screws which are distributed along the length of the bar 6, theleather may be set snugly against the roll at every point in its length,and compressed laterally to have more or less elasticity as demanded. Bylong continued practical tests I have demonstrated the fact that theleather scraper will keep the surfaces of the rolls clean in grindingall classes of grain, and grain products, and in humid as well as in dryatmospheres. It will not scratch or injure the surfaces of the rolls. Itwill yield to a limited extent, and closely hug the roll at every pointand will not, like brushes, retain the material. Unlike the customarymetal blades the leather will yield or bend edgewise under the influenceof the adjusting screw so that its pressure may be properly graduated atevery point in its length.

The supporting bar may be continuous from end to end, and secured firmlyto the frame or other rigid support in any suitable manner, as byseating its ends in plates E, such as shown in Fig. 3, bolted to theinside of the frame. When, however, it is desired to adapt the scraperfor convenient attachment to existing mills, I make the bar I)extensible so that it may be elongated and seated at its ends firmlyagainst the inner sides of the mill frame. A good construction to thisend is shown in Figs. 2 and 4, in which it will be seen that the bar I)is divided-transversely, and the two parts united by a screw g, by whichthey may be forced apart and seated at their ends firmly against theinside walls of the frame or other roll supports. To prevent the barfrom springing or bending I propose when necessary to connect the twoparts by a sliding splice plate h, seated in grooves therein. The plates0 and d are continuous across the break in the bar b, as shown.

In practice it is found that leather, in consequence of its peculiarnature, differs in its action upon the roll from any other material nowin use. When properly supported, as herein shown, it possessessufficient rigidity to bear against the roll and remove the adheringmatters without, however, scratching or otherwise injuring the surfaceof the roll, as a metal scraper is liable to do. As compared with ametal scraper it is also advantageous in that it is sufficientlyflexible to adapt itself to the surface of the roll at every point inits length. Brushes as commonly employed are liable to become cloggedand loaded with the product from the rolls, which material souring orfermenting, frequently injures the material with which it may be mixed.

I do not claim broadly the combination of an elastic scraper with aroll, nor broadly the substitution of a leather scraper for scrapers ofother material, but

What I do claim is,

1. As an improvement in roller grinding mills, the combination of thesmooth grinding roll, the fixed channeled support 0, the flexible metalstrip 0, therein, the leather strip seated in said support against theflexible strip and bearing edgewise against the roll, and the series ofadjusting screws beneath the strip at different points in its length asshown: whereby the leather is sustained and held ad justably in contactwith the roll. 2. In a roller grinding mill, and incombination with thesmooth grinding roll, the leather strip presented edgewise against theroll, the fixed grooved support 0, the fiexible strips 0, d, thereinbearing beneath and against the side of the leather, and the adj listingscrews e,f, applied as shown: whereby the leather is compressed,sustained and held adjustably in contact with the roll.

DANIEL ALBERT SCALLEN.

Witnesses:

W. B. PETER, '1. H. HUNT, Jr.

